#ifndef __HALTON_H
#define __HALTON_H

class Halton2 {
	
	float _invBases[2];
	float _prev[2];

	float halton(float baseRec, float prev) const {
		float r = 1 - prev - 1e-10;
		if (baseRec < r) return prev + baseRec;
		float h = baseRec;
		float hh;
		do {
			hh = h;
			h *= baseRec;
		} while (h >= r);
		return prev + hh + h - 1;
	}
	
public:

	void Reset() {
		_prev[0] =_prev[1] = 0;
	}

	Halton2() {
		_invBases[0] = 1./2;
		_invBases[1] = 1./3;
		Reset();
	}
	
	void
	GetNext(float &a, float &b) {
		a = halton(_invBases[0], _prev[0]);
		b = halton(_invBases[1], _prev[1]);
		_prev[0] = a;
		_prev[1] = b;
	}
};

extern Halton2 halton2;

#endif